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May 3, 2012 -- When lupus attacks the kidneys, the damage can be life-threatening. Now, updated guidelines from the American College of Rheumatology are aimed at identifying kidney involvement in lupus early and treating it aggressively to stop this damage in its tracks.

Systemic lupus erythematosus (SLE), or lupus, is an autoimmune disease that occurs when the body's immune system mistakenly attacks its own tissues. Some symptoms include rashes, joint pain, and fatigue.

About 1.5 million Americans have lupus, and one-third of them will develop kidney involvement, or lupus nephritis, as a result, according to the Lupus Foundation of America. Most at risk for lupus nephritis are African-Americans under the age of 25 and children with lupus. African-American men are considered high risk. Just recently actor and rapper Nick Cannon, husband of Mariah Carey, told various media outlets that he has lupus nephritis.

It is often silent, but lupus nephritis symptoms may include:

Weight gain

Fatigue

High blood pressure

Dark urine

Swelling around eyes, legs, ankles, or fingers

New Guidelines Focus on Early Diagnosis of Lupus Nephritis

Guideline co-author Bevra Hahn, MD, a professor of medicine at the University of California, Los Angeles, and colleagues reviewed the literature for studies on lupus kidney disease to come up with a plan on how to better diagnose and manage this condition. Last updated in 1999, the new guidelines appear in Arthritis Care and Research.

According to the guidelines, a kidney biopsy is a consideration in all people with lupus who show signs of active kidney involvement.

"With earlier diagnosis and treatment, we really minimize the damage caused by lupus nephritis," says Joan T. Merrill, MD. She is the medical director of the Lupus Foundation of America and one of the authors of the new set of guidelines.

This is important as early kidney involvement is often silent, says Merrill. "Doctors should be watching the urine and seeing if there is any evidence of kidney disease. Theoretically, we should be able to pick up kidney involvement before it gets symptomatic." Merrill is also a professor of medicine at the University of Oklahoma Health Sciences Center in Oklahoma City.

Biopsy is the best way to identify kidney disease early, says Sandra C. Raymond, the president and CEO of the Lupus Foundation of America in Washington D.C. "It is the quintessential diagnosis tool for lupus nephritis. They can tell whether it is lupus or not that is causing the symptoms."

The guidelines also state that people with lupus nephritis may benefit from "background treatment" with the anti-malarial drug hydroxychloroquine to prevent damage to the kidney and elsewhere in the body.

Guidelines Discuss Treating Flares

There are also more options to treat active lupus nephritis today than ever before.

The new guidelines may help persuade insurers to cover the costs of some of the newer drugs.

There is trial and error involved in getting the disease under control. "If people aren't improving by six months, they should switch to another therapy," Hahn says. "If they are worsening at three months, they should switch to another treatment."

Pregnant women with lupus nephritis present a special challenge. Many of the available drugs can't be used during pregnancy.

"We don't know how rapidly you can taper off of or stop these treatments without risking a flare when a patient wants to become pregnant, either," Hahn says.

Still, LFA's Raymond adds: "Lupus nephritis care has come a long way in the past two or three decades. Today's medication can stop the disease from progressing."

And the new guidelines will pave the way for future advances, says David Pisetsky, MD, in an email. He is the chief of rheumatology at Duke University Medical Center in Durham, N.C.

"These guidelines are very important to the care of patients as well as research, including clinical trials of new agents and treatment approaches," he says. "They are a needed foundation for future work."